Beauty Comparison
Shop by need
Eczema-prone skinRosacea-prone skinSensitive skinFragrance-freePerfume allergyAcne-prone skinFungal acnePsoriasisPregnancyDry skin
Buying guides
Fragrance-Free MoisturizersMoisturizers for Sensitive SkinMoisturizers for Acne-Prone SkinFragrance-Free CleansersFragrance-Free SunscreensFragrance-Free ShampoosCleansers for Sensitive SkinCleansers for EczemaCleansers for Acne-Prone SkinSunscreens for Sensitive Skin
Products
SkincareHaircareMakeupBodySun careMen's groomingBabyNailsFragranceTools
Ingredients
Tools
Free-from finderIngredient checkerBrand comparisons
Learn
SkincareHaircareMakeupNails, Body & FragranceHormones & Wellbeing
USCAUKDEFRITESNLPLSE

Ingredient dictionary

Potassium Nitrate

Also listed as: Saltpeter

Potassium Nitrate is a mineral salt made from potassium and nitric acid, mainly used in toothpaste to help calm sensitive teeth. Checked against our library November 6, 2026.

What Potassium Nitrate does

  • Helps calm sensitivity to hot and cold
  • Acts as a desensitizing agent in oral care
  • Often paired with fluoride in toothpaste

Potassium nitrate is a salt made from potassium and nitric acid. It occurs in nature as a mineral, but most of the supply used today is made by chemical process. In personal care it is best known as a desensitizing ingredient in toothpaste.

Formulators choose it because its potassium part is thought to reach the nerve inside a tooth and calm the discomfort that comes from hot, cold, or sweet foods. It dissolves well in water, so it blends evenly into a paste.

Good for

Suits people with sensitive teeth who use toothpaste and want a daily desensitizing option.

Frequently asked questions

Is potassium nitrate safe in toothpaste?

Potassium nitrate is a common toothpaste ingredient for sensitive teeth and is used in many toothpastes sold around the world. It is generally well tolerated. If your teeth stay sensitive or hurt, ask a dentist, since sensitivity can have other causes.

Is potassium nitrate the same as saltpeter?

Yes. Saltpeter, also spelled saltpetre, is an old common name for potassium nitrate. It is the same chemical. You may see the older name in historical texts.